First full-length outing for these long-time collaborators, in Niven’s (Ringworld’s Children, 2004, etc.) world-building tradition—literally.
With Earth succumbing to rampant nanotechnology and rogue Artificial Intelligences, starship John Glenn (the first of three) headed for distant Ymir, an uninhabitable planet that could be terraformed. When its engines malfunctioned, however, John Glenn had barely enough fuel to limp to the gas giant planet, Harlequin. In order to create more antimatter fuel, the crew needs a base—so they set about constructing a moon, Selene, from Harlequin’s orbiting debris. Children are trained to work but told little of the true circumstances. Kindhearted Gabriel undertakes to teach the Moon Born, singling out smart, beautiful Rachel as a future leader. But council leader Liren ensures that Rachel learns only what the council wants her to know. Slowly, Rachel realizes that she and the other Moon Born are slaves, that Selene will never be stable enough to support them in the long term, and that Liren is coldly determined to abandon them once the fuel is ready (there’s not enough room for them on the ship) and proceed to Ymir. Rachel becomes acquainted with other dissidents: old Treesa on the ship, the artificial intelligence called Astronaut (more self-aware than the council suspect, it fears reprogramming) and Astronaut’s secret copy, Vassal. Despite her growing comprehension and increasing collection of allies, Rachel can see no way to break the council’s iron grip.
Despite many agreeable details, there’s little to be done with such a far-fetched and overelaborate setup; practically from page one the narrative settles into a comfortable rut and thereafter stays its entirely predictable course.